The Davis Lake area contains three andesitic Holocene cinder cones and associated fresh-looking lava flows along a N-S line at the base of a group of Pleistocene basaltic andesite shield volcanoes east of the crest of the Cascade Range, south of the Mount Bachelor volcanic chain. The northernmost lava flow created a natural barrier forming Davis Lake and lies at the western base of the Pleistocene Davis Mountain shield volcano and at the SW end of Wickiup Reservoir. The two southern flows are in a flat-lying area straddling Crescent Creek between Hamner and Odell Buttes. The middle lava flow was erupted from a small breached cinder cone on the lower southern flank of Hamner Butte and was radiocarbon dated at 4,740 years before present. The southernmost lava flow originated from a cone at the ENE base of Odell Butte. All three lava flows were probably erupted at about the same time.